This invention relates to a gas turbine engine component and, more particularly, to components having an internal cooling passage with trip strips that vary in orientation along a length of the cooling passage.
A variety of different machines, such as gas turbine engines, typically include components that operate under elevated temperatures. To resist the elevated temperatures, the components traditionally employ a cooling system. For example, relatively cool air is taken from air flow through the engine and conveyed through internal cooling passages of a turbine blade within the engine. Depending on the particular design of the turbine blade, the cooling passages may include a series of trip strips to promote turbulence, which in turn enhances heat transfer within the cooling passage.
Although effective, there are opportunities in several aspects to improve typical cooling systems that utilize trip strips. For example, the arrangement of the trip strips is typically uniform throughout the passages to promote uniform cooling and heat transfer. However, depending on the turbine blade design, the need for heat transfer may not be uniform because of the difference in sizes of the passages and differences in hot gas flow over outer surfaces of the turbine blade adjacent the passages. Also, the trip strips obstruct air flow through the passages, which results in a pressure drop through the cooling passages that contributes to engine inefficiency by requiring a larger mass flow of input air for cooling.
Therefore, what is a needed is an arrangement of trip strips for enhanced heat transfer and less air flow obstruction. This invention addresses these needs while avoiding the shortcomings and drawbacks of the prior art.